Bayer Expert Guide Meadow-grass Management in Winter Cereals

www.bayercropscience.co.uk Introduction

Copyright of photographs The term ‘meadow-grasses’ refers broadly to a group of around fifteen Poa species found in the UK. A few species are widespread All photography © Bayer CropScience Ltd 2015, except where indicated. and common; others very rare with only three of significant importance to the farmer. These are annual meadow-grass (Poa annua), rough meadow-grass (Poa trivialis, also known Active substances and trademark acknowledgements as rough-stalked meadow-grass) and smooth meadow-grass (Poa pratensis, also known as smooth-stalked meadow-grass). Atlantis®, Bacara®, biopower®, DFF ®, Liberator®, Movon®, Othello® and Vigon® are registered trademarks of Bayer. Of the three, both annual meadow-grass and rough meadow-grass are commonly found as weeds in arable and horticultural crops Atlantis WG contains mesosulfuron-methyl and iodosulfuron-methyl-sodium. Bacara contains diflufenican and flurtamone. (1,9,38,41,43). Liberator contains flufenacet and diflufenican. Othello contains diflufenican, iodosulfuron-methyl-sodium and mesosulfuron-methyl. Movon and Vigon contain flufenacet, diflufenican and flurtamone. Although smooth meadow-grass is widespread The objective of this booklet is to aid and assist Use plant protection products safely. and frequently found as a constituent of pastures, in the identification of these more common Always read the label and product information before use. grassy banks, roadside verges and field margins, meadow-grasses, and give an insight into their Pay attention to the risk indications and follow the safety precautions on the label. it is not usually a serious or persistent problem distribution and biology, and guidance on their For further information, please visit www.bayercropscience.co.uk or call Bayer Assist weed in arable crops (1,41). It is most often seen control in winter cereals. on 0845 6092266 (calls cost 5p per minute plus your telephone company’s network as an arable weed following ploughed up access charge) or 01223 226644. permanent pastures or grass seed crops (36).

© Bayer CropScience Limited 2015.

2 3 Contents

1 Distribution of meadow-grasses 6 2 Economic implications of meadow-grass infestations 8 3 Reasons for the presence of meadow-grasses 9 4 Growth habit, biology and characteristics of meadow-grasses 10 4.1 Annual meadow-grass 10 4.2 Rough meadow-grass 10 4.3 Smooth meadow-grass 11 4.4 Identification characteristics of meadow-grasses 11 5 Meadow-grass control 14

5.1 Preventing new infestations 14

5.2 Herbicide resistant weeds 14

5.3 Key herbicides available for the control of meadow-grasses 15

6 Use of Othello for meadow-grass control in winter cereals 17

7 References 18

Meadow-grass

4 5 1 Distribution of meadow-grasses

Whilst annual, rough and smooth meadow-grass are widespread and More recently in 1998/99, another survey of 569 Source GfK Kynetec. arable field headlands in the UK found that annual found in every county in the British Isles (2,3), only annual and rough meadow-grass occurred on around 40% of those meadow-grass are commonly found in arable crops. covered – making it almost twice as common as rough meadow-grass and almost five times more common than smooth meadow-grass (34). In 1981, a survey of winter wheat and barley crops Rough meadow-grass was considerably less conducted throughout Central Southern England, common, with the highest frequency being A survey in 2011 of 1,350 arable farmers in Britain reported that meadow-grasses (predominantly recorded in some areas of mixed farming. showed that 34% of farms applied herbicides Figure 1 annual and rough meadow-grass) were present The least common was smooth meadow-grass, specifically to control meadow-grass species (45) in 35% of fields throughout the area (24). the highest frequency being found in South East (Figure 1). The darkest red indicates the areas of Subsequent studies have shown that both annual and North Wales – and on average in only around most intensive herbicide usage specifically for and rough meadow-grass can also be found in 20% of fields visited. Throughout the remainder meadow-grass control. The paler areas in the spring-sown cereals (9,36,37,43). of Britain the frequency was around 10-20% of south and east of England however, do not fields infested (30). necessarily indicate a low incidence of meadow- A survey in 1991/92 showed annual meadow- grass. It is more likely that herbicides used for other grass to be the most common of the three Table 1 gives an indication of the areas worst and problem grasses, such as black-grass, have also meadow-grasses, being both very frequent and least affected by these three species. controlled meadow-grasses as a secondary target widely distributed in arable fields throughout Britain. weed in these counties.

Table 1: Relative frequency of annual, rough and smooth meadow-grass throughout Of the remaining twelve species of meadow-grass Britain (1991/92) found in Britain (Table 2), nine are either rare or very rare – confined mainly to mountainous or rocky areas; and three, whilst frequent, are only found in Species Areas recorded as most Areas recorded as less woodlands, shady areas or on thin, dry soils. All are common common Key: Incidence of spraying for meadow-grasses unlikely to be encountered in arable situations (1). Annual meadow-grass Kent, Surrey, Sussex, Bedfordshire, Essex, Hampshire, Isle of Wight, Cambridgeshire, North Common throughout Britain: Berkshire, Norfolk, Teesside, Lincolnshire and Humberside, found in around 40-100% Lowest Highest Durham, Lancashire, Cumbria, South Yorkshire, South Wales, of fields surveyed Figure 1: Intensity of herbicide use for Cornwall, West and North Argyll and Bute meadow-grass control in cereals 2011 Wales, Northumberland, Dumfries and Galloway Rough meadow-grass Powys, Isle of Man, Hampshire, East Anglia, Bedfordshire, Table 2: Other meadow-grasses (Poa spp.) found in Britain Isle of Wight, Berkshire, Kent, Oxfordshire, Somerset, Occurs throughout Britain Surrey, Sussex, Wiltshire, Avon, Lincolnshire, South Yorkshire, but only found in 10-60% East and West Midlands, Lancashire and Cumbria, North Early meadow-grass Poa infirma H.B.K. Glaucus meadow-grass Poa glauca Vahl. of fields surveyed Gloucestershire Wales, Central and North Bulbous meadow-grass Poa bulbosa L. Swamp meadow-grass Poa palustris L. Scotland Alpine meadow-grass Poa alpina L. Broad-leaved meadow-grass Poa chaxii Vill. Smooth meadow-grass Monmouthshire, Dorset, Hertfordshire, Nottinghamshire, Berkshire, North Wales and Bedfordshire Wavy meadow-grass Poa flexuosa Sm. Narrow-leaved meadow-grass Poa angustifolia L. Occurs across Britain, but only Anglesey, Northumberland and Wood meadow-grass Poa nemoralis L. Spreading meadow-grass Poa subcaerulea Sm. found in a maximum of 20% Durham, South West Scotland of fields surveyed Balfour’s meadow-grass Poa balfouri Parv. Flattened meadow-grass Poa compressa L.

6 7 2 Economic implications of meadow-grass 3 Reasons for the presence of meadow-grasses infestations

Weed competition can impair cereal establishment Although not as competitive as some other annual In contrast to black-grass and brome grasses, the reasons for the and growth, resulting in reduced yields or poor grass-weeds, such as wild oats and bromes, grain quality. Where grass-weeds are present in the effects of meadow-grasses on crop yields presence of meadow-grasses are less clear-cut. cereals the incidence of Barley Yellow Dwarf Virus are not insignificant. Rough meadow-grass for (BYDV) and some fungal pathogens, such as ergot example, is more competitive, plant for plant, The increase in frequency of grass-weeds in cereals (Claviceps purpurea), may also be increased. than black-grass (9,36). may be partially attributed to the widespread use Lodging caused by weeds can also make of both hormone-based, and other broad-leaved Of the two ‘problem’ meadow-grasses, rough harvesting difficult, time consuming and reduce weed herbicides throughout the late 1950’s to mid meadow-grass is the more competitive. Table 3 grain quality (36). 1960’s. It has been suggested their use caused a compares the competitive effect of some annual decline in susceptible broad-leaved species, leaving If uncontrolled, particularly in thin crops and under grass-weeds on winter wheat yields. grass-weeds uncontrolled and with potentially less moist growing conditions, meadow-grasses can competition (4,5,6,11). rapidly take hold to form a dense mat at the base Whilst there is little evidence on the competitive of the crop. effects of smooth meadow-grass in cereals, it is Annual meadow-grass is found on most soil types anticipated that, where it exists, it is likely to be and in most situations – especially where land is Even moderate populations of annual meadow- comparable to that of rough meadow-grass, as disturbed. It is dispersed on the wind and by both grass can still give rise to a decrease in cereal it is of both similar size and growth habit. animal and human intervention. It is therefore yields of up to 6%, although with very dense unsurprising that it is a very common weed in infestations (greater than 1,000 plants/m2), losses both UK agriculture and horticulture. of up to 25% have been recorded under moist conditions (10). In contrast, rough meadow-grass is essentially a perennial pasture grass that has gradually moved into arable cropping as pastures have been 2 Plant No. of plants/m ploughed up, particularly in mixed farming areas. Wild oat (Avena spp.) 0.5 In other areas it has also moved in from grassy field margins and field tracks, being spread by seed and Brome grasses (Bromus spp.) 3 vegetative means (22). Rough meadow-grass (Poa trivialis) 5 Direct drilling and minimal cultivations also favour Black-grass (Alopecurus myosuroides) 8 the germination and emergence of meadow- grasses, as most of their seeds (being stimulated Table 3: Number of plants shown to give a 2% yield reduction in winter wheat by light) germinate on or close to the soil surface (7,35). This minimal soil disturbance may also encourage perennial species to regenerate from clumps that are not buried below the soil surface. Smooth meadow-grass

8 9 4 Growth habit, biology and characteristics of meadow-grasses

4.1 Annual meadow-grass flowers and seeds throughout the year, both Seeds germinate under a wide range of 4.4 Identification characteristics of emerging and flowering plants can sometimes be temperature and moisture conditions. Those meadow-grasses Annual meadow-grass is found across a range seen in close proximity to each other. emerging before the winter will have both more, of habitats in over 80 countries with temperate and earlier, flower heads than those emerging Correct species identification is key to good Although annual meadow-grass flowers climates, and in cooler areas of tropical regions. during the winter or spring (32). As with annual weed control, although with meadow-grasses independently of day length, seed head production It is reported to be a weed in over 38 crops meadow-grass, the germination of rough this can be difficult while they are still at the is at its maximum in May and June, with seeds worldwide and therefore probably one of the most meadow-grass seeds is also stimulated by light. early vegetative stages. becoming viable only 1-2 days following pollination common grass-weeds in all crops (12,16). It is Low temperatures have an inhibitory effect on frequently one of the most common weed seeds (17,18). It is capable of producing large numbers of germination (35). Annual meadow-grass (Poa annua) found in soil seed banks. seeds; sometimes a single plant may produce up to 13,000 seeds, more under some circumstances. Rough meadow-grass tolerates shade, and grows In the UK it exists as both an annual and short-lived best on moist, nutrient rich soils that are slightly Annual meadow-grass can be found in winter perennial, although in arable situations it is most acid to neutral. It can also be found on clay loam Ligule: Medium: 2-5 mm cereals from autumn onwards (25), frequently likely to be encountered as an annual plant. As a and chalky soils, and only occasionally on sandy Roundly pointed and serrated. on the headland areas of fields. It is also a rapid perennial, it is more commonly found in moist soil types. As with annual meadow-grass, it is also coloniser of set-aside land (28), although in the long undisturbed, sandy conditions, where prostrate sensitive to drought. growth allows rooting at the nodes, enabling term, and in the absence of bare ground, it may be vegetative spread as well as that from seed (1,11). out-competed by perennial species (26,27). 4.3 Smooth meadow-grass Auricles: Absent. It is predominantly a self-pollinating grass. Seeds It does not thrive under drought or very acid Smooth meadow-grass is also a perennial and, like are spread by wind, human activity, by animals and conditions, or in soils low in phosphates (21). rough meadow-grass, is common in pastures and birds, in water and on farm implements. It is also undisturbed grassy areas. It spreads essentially 4.2 Rough meadow-grass the most abundant weed seed to be found in soil by rhizomes rather than stolons, and flowers from on footwear (11,19). In contrast to annual meadow-grass, rough May to early July. It is a very variable species with meadow-grass is essentially a perennial plant. several sub-species, some strains of which may Leaf blade: Light green with Annual meadow-grass germinates throughout the boat-shaped tip. Blade often When mature, it is loosely tufted and spreads by produce viable seed without fertilisation (1). It can year, with the period of maximum emergence from crinkled or puckered and both creeping leafy stolons and seeds. It occurs in survive in poor soils that are moderately acid to April through to September, the latter being the hairless. It is slightly keeled, a wide variety of habitats, but is more commonly alkaline, although it has a preference for light, with ‘tramlines’ and is folded optimum time, possibly due to more reliable soil found in pastures, roadside verges, waste-ground, sandy soils that are well drained and rich in in shoot. moisture (20,43). After this, as the temperature and field margins (22,23,42). Nevertheless, when nutrients. It has good drought and cold resistance. falls, germination gradually decreases. From the present in arable crops, plant for plant, it is more middle of February, germination increases again It grows from near sea level up to several thousand competitive than annual meadow-grass. with rising temperature (7). The minimum feet, and is common throughout Europe, temperate temperature for germination is 2-5 ˚C, optimising Flowering occurs mainly in June and unlike annual Asia and North America where it was introduced from around 7 ˚C, through to a high of 35 ˚C (30). meadow-grass pollination is primarily by wind. as a sports turf and pasture grass (Kentucky Seeds are shed until August and require blue-grass). In Britain, some strains are also used Emergence also increases with increasing soil vernalisation to flower the following year. Seedlings in mixtures with other grasses for the same Flowering head: Branched and moisture (up to a maximum of 40% of field spreading, triangular in outline. emerging in the late spring are therefore unlikely to situations (1). capacity), indicating that moisture retentive soils Spikelets are small and awnless. set viable seed. (including those with higher levels of organic matter) may be more prone to annual meadow- In cereal crops, rough meadow-grass may produce grass problems (16). Dry conditions however between 1,000 and 14,000 seeds per plant, but in delay emergence. open situations it can produce twice this number (39). Reproduction from seed therefore is an important Once established, it forms either a loose or factor in the spread of this perennial grass (7). compact erect, tufted plant and will flower within 44-55 days of germination (1,15). Because it

10 11 Rough meadow-grass (Poa trivialis) Smooth meadow-grass (Poa pratensis) Species Annual meadow-grass Rough meadow-grass Smooth meadow-grass Scientific name Poa annua Poa trivialis Poa pratensis

Ligule: Long: 4-10 mm Ligule: Lower – very short. Plant Annual (or short-lived Perennial with stolons Perennial with rhizomes Pointed and membranous. Upper – short: 1-3 mm. perennial rooting at the Longest on top leaves. nodes) Height Up to 30 cm Up to 100 cm Up to 90 cm Auricles: Absent. Auricles: Absent. (including flower head) Leaf blade Colour Light green Green or purplish Green or greyish-green Characteristics Boat shaped tips, Acutely pointed boat Pointed or blunt boat blades often crinkled shaped tips shaped tips Leaf blade: Green and Leaf blade: Dull green or hairless, with boat-shaped tip. greyish-green with boat-shaped Width Up to 5 mm 1.5-5 mm 2-4 mm Minutely rough and abruptly tip. Upper ribless and dull; pointed. Lower glossy and lower keeled. Hairless with Length Up to 14 cm Up to 20 cm 20-30 cm keeled, with ‘tramlines’ folded ‘tramlines’ and folded in shoot. in first, opening later. Leaf surface Hairless Hairless Hairless or minutely hairy Ligule Lower stem base leaf Lower stem base leaf sheaths: Usually feel rough. sheaths: Usually smooth. Length 2-5 mm 4-10 mm Upper 1-3 mm Generally bright green but Shape Roundly pointed, Pointed, serrated Collar shaped, smooth can be purplish. slightly serrated Leaf sheaths Smooth Usually rough Smooth Flowering head: Branched and Flowering head: Branched and Panicles (seed heads) spreading, but can be contracted spreading, but can be contracted and dense. Spikelets are small and dense. Spikelets are small Length Up to 12 cm Up to 20 cm Up to 12 cm and awnless. and awnless. Width Up to 8 cm Up to 15 cm Up to 12 cm Spikelets (length of a 3-10 mm 3-4 mm 4-6 mm unit seed group)

Table 4: Characteristic features of the three key meadow-grass species

Glossary to Table 4: Leaf sheath – Part of the leaf that grasps the stem. Stolon – Above ground creeping stem, rooting at Panicle – The compound flowering head or ear of the nodes to form further vegetative shoots. a grass, to which each spikelet has a distinct stalk attached to the main stem. Rhizome – Underground creeping stem, rooting at the nodes to form further vegetative shoots. Spikelet – Single unit of grass flower head. Ligule – Upright pale/white, membranous extension (Compiled from 1,12,13,14,31.) at the junction of the leaf sheath and leaf (blade).

12 13 5 Meadow-grass control

It was not until the late 1960’s and mid 1970’s when the first of the 5.3 Key herbicides available for the than 2-3 inches (5-8 cm) in diameter and the control of meadow-grasses seedbed consolidated. For pre-emergence selective, broad-spectrum, substituted urea herbicides were applications a moist soil surface with some rainfall introduced into cereals, for example metoxuron, chlorotoluron (CTU) The information contained within this sub-section soon after application will also help maximise the has been taken from a number of sources; it is level of control provided. and isoproturon (IPU). Control of annual grass-weeds in cereals then for information only and does not constitute any became a more common practice (7,8). specific recommendation for the control of Chlorotoluron (CTU) – A contact and residual urea meadow-grasses or other weeds in winter cereals. herbicide available in mixture with pendimethalin and diflufenican effective against meadow-grasses For many years it has been considered critical to The onset of meadow-grass problems may be A number of active ingredients are available for the and a range of broad-leaved weeds. Follow control wild oats, cleavers, bromes and black-grass reduced by: chemical control of meadow-grasses and other stewardship guidelines to avoid movement of CTU in winter cereals. Control of other weeds such as weeds in cereals (29). The list provided is not  Sowing spring cereals or other spring crops to surface waters. meadow-grasses, mayweeds, poppies, Italian exhaustive and serves only to give an indication in the rotation rye-grass and volunteer rape and beans should of the herbicides currently available at the time of Isoproturon (IPU) – A contact and residual urea also be considered a priority where they are a  Delaying the final cultivations of ploughed going to press. The levels of control provided by herbicide for use in a number of cereal crops. It is problem (40). pasture or old infested grass-seed crops (32) these herbicides differ depending on a range of active against meadow-grasses, including rough factors including the intrinsic level of activity of the meadow-grass, and a limited range of broad-leaved Like most other weeds, meadow-grasses rarely  Including cultivated boundary strips around herbicide and the growth stage of the meadow- weeds. Follow stewardship guidelines to avoid grow in isolation and may be found with both a field, used as part of an overall strategy to grass at application. Also note that not all the movement of IPU to surface waters. broad-leaves and other grasses. In the very early prevent the encroachment of weeds, rather herbicides listed are effective against both the stages of growth, meadow-grasses are relatively Diflufenican (DFF®) – A residual, shoot absorbed than as a single operation major meadow-grass species (annual and rough). easy to control with appropriate herbicides, but herbicide for mainly broad-leaved weed control once established, or as mature perennials, control 5.2 Herbicide resistant weeds Restrictions may apply to application timings, in winter cereals with some activity on meadow- grasses. For broad spectrum control it is formulated becomes much more difficult. There are confirmed strains of annual meadow- crops and following crops. In all cases either check with other herbicides including flufenacet (e.g. Liberator) grass resistant to herbicides (mainly paraquat) with your advisor or follow guidelines provided in 5.1 Preventing new infestations and flurtamone (e.g. Bacara). in orchards. There is NOT, however, currently a product literature or on the product label. Individual products must be applied in accordance with After ploughing up established pastures, ensure problem with herbicide resistant meadow-grasses Flufenacet – A residual oxacetamide herbicide for directions and restrictions on the product label. any clumps of surviving grasses are killed before in arable situations in Britain. pre and early post-emergence grass-weed control in Always read the label and product information sowing the next crop. This is particularly important winter wheat and winter barley. Available in mixtures Whilst this is the case, any herbicide strategy before use. Use plant protection products safely. in the case of both rough and smooth meadow- (e.g. with diflufenican as Liberator) it can provide considered should take account of any other Where tank-mixes are used, the manufacturers’ grass, as these can form the basis of future weed high and consistent levels of control of both annual annual grass-weeds present in the crop. recommendations should always be followed. infestations. and rough meadow-grasses. Some strains of other grass-weeds, e.g. black- Residual herbicides Before moving from field to field, or storing the Flurtamone – A residual, primarily root absorbed, grass, wild oats and Italian rye-grass, have combine, clean any obvious concentrations of bleaching herbicide for pre and early post-emergence developed resistance to herbicides in arable crops; Residual herbicides can provide control of weed seeds and crop residue from within the grass and broad-leaved weed control in cereals. this may lead to poor control. If they are present, meadow-grasses emerging after application and, combine. This will help to reduce the transference Available only in mixtures (e.g. with diflufenican as a strategy for preventing and managing such as such, are a valuable component of a control of weed and (volunteer) crop seeds from one field Bacara) it provides moderate levels of control of resistance should be adopted as appropriate. programme when applied either pre-emergence or to another. very early post-emergence. For any soil acting meadow-grasses and is typically used in tank-mixes It should be noted that, unless CRD have granted herbicide, seedbed preparation is particularly or sequences with other herbicides for improved approval for a sequence, only one application of important to get the optimal level of control. levels of control. Also available in co-formulation an ALS inhibiting grass-weed herbicide should be Accumulations of chopped straw or crop residue with flufenacet + diflufenican as Movon/Vigon it made to the crop throughout its growing season. should be buried, or spread as thinly as possible, enhances further the consistent level of control following cultivation. Ideally, clods should be smaller provided by the other component actives. For further information, consult guidelines issued by the Weed Resistance Action Group; copies are available from the HGCA, CPA, your distributor, crop advisor or product manufacturer.

14 15 6 Use of Othello for control of meadow-grass in winter cereals

Pendimethalin – A residual dinitroaniline herbicide Mesosulfuron-methyl – A sulfonylurea herbicide Othello is a post-emergence herbicide that delivers the most effective for use in cereals and other crops. It is effective, (ALS inhibitor) providing post-emergence control pre-emergence, against annual meadow-grass but of a wide range of annual grasses in winter wheat, and consistent control of emerged annual and rough meadow-grass rough meadow-grass is less susceptible. It should including both annual and rough meadow-grass. in winter wheat when used appropriately. In addition it controls a wide be applied as soon as possible after drilling, as its It currently provides the most robust post-emergence efficacy is reduced against emerged grass and treatment for meadow-grass control up to tillering range of key broad-leaved weeds frequently found in association with broad-leaved weeds where used alone. Also stages. Mesosulfuron is available in mixture with meadow-grass infestations. This section provides a brief summary of available co-formulated with flufenacet, which iodosulfuron and diflufenican (as Othello) for the the information relating to the effective use of Othello (mesosulfuron + provides improved levels of control of meadow- post-emergence control of meadow-grasses and grasses, or with picolinafen for improved levels a range of broad-leaved weeds in winter wheat. iodosulfuron + diflufenican). of post-emergence control. Pinoxaden – A phenylpyrazoline herbicide (ACCase Efficacy Resistance management – A thiocarbamate herbicide for inhibitor) controlling annual grasses in winter wheat, Prosulfocarb  For the most consistent post-emergence control  Due to the risk of resistance development in both pre and early post-emergence weed control winter barley and spring barley. It can provide control of meadow-grass, apply Othello at 1.0 L/ha with other annual grass-weeds do not use Othello in cereals. It controls both annual and rough of rough meadow-grass, but does not control the adjuvant biopower at 1.0 L/ha up to early specifically for the control of annual grass-weeds meadow-grass and a limited range of broad-leaved annual meadow-grass or broad-leaved weeds. tillering (GS 23) of meadow-grass ensuring good other than meadow-grasses. Where weeds weeds. Typically recommended in tank-mix with spray coverage of the weeds such as black-grass are present in significant diflufenican or pendimethalin for improved levels numbers, the use of an alternative product  Othello should be applied to young actively and spectrum of control. (e.g. Atlantis WG) will be more appropriate growing weeds for maximum efficacy and when Post-emergence herbicides the majority of meadow-grass has emerged,  Do not use any other grass-weed active ALS Clodinafop-propargyl – A foliar applied ‘fop’ typically in the autumn inhibiting herbicide in sequence or tank-mix with herbicide (ACCase inhibitor) providing post- Othello unless the ALS sequences/tank-mix is  As meadow-grass infestations frequently consist emergence control of annual grass-weeds but with approved by CRD of plants at various growth stages, aim to apply no residual control, nor control of broad-leaved Othello prior to tillering, as later applications may  Do not use Othello as the sole means of weeds. It is effective against rough meadow-grass, result in some plants beyond susceptible growth grass-weed or broad-leaved weed control in but not against annual meadow-grass. stages and reduce levels of control successive crops. Always use grass and – A sulfonylurea herbicide broad-leaved weed herbicides with non-ALS Flupyrsulfuron-methyl  Othello applied beyond early tillering of meadow- (ALS inhibitor) used for the pre and post-emergence modes of action throughout the cropping rotation grass, or in the spring, can reduce profitability control of annual grass and broad-leaved weeds in due to poorer control and/or reduced yields  Monitor weed control effectiveness and winter wheat (and pre-emergence only in winter investigate any odd patches of poor grass Crop tolerance barley). Active by a combination of foliar and root or broad-leaved weed control. If unexplained  Avoid application to ‘soft’ crops as crop effects uptake, its post-emergence efficacy is enhanced a resistance test may be appropriate by moist soil conditions. Meadow-grasses are only (yellowing) may be observed following treatment, moderately susceptible to flupyrsulfuron-methyl. particularly on spray overlaps and for late season/spring applications. These effects are transitory in nature and will normally have no adverse effect on grain yield

16 17 7 References

1 – Hubbard, C. E. – Grasses: A guide to their structure, identification and distribution in the British Isles 25 – Turner, M. T. F. – Rhone-Poulenc Agriculture – Boarded Barns Farm: Field and Margin Flora Survey, (revised 1972), pp. 169,187,191 2nd, 3rd, 5th and 6th Annual Reports 2 – Perring, F. H. and Walters, S. M. – Atlas of the British Flora. (1962) 26 – Davies, D. H. K., Fisher, N. M. and Atkinson, D. A. – Weed control implications of return of set-aside land to arable production. BCPC Monograph. No.50 – Set-aside. (1992) pp. 129-134 3 – The National Crop Disease and Weed Survey, 1991/1992, pp. 1, 15, 16 27 – Wilson, P. J. – The natural regeneration of vegetation under set-aside in Southern England 4 – Fryer J. D., and Chancellor, R. S. – Evidence of changing weed populations in arable land. Proceedings of 1970 Br. Weed Control Conf., pp. 958-964 28 – Wright, B. E. and Bonser, R. – The influence of field boundaries on re-colonisation of set-aside. BCPC Monograph No. 50 – Set-aside. (1992) pp. 139-142 5 – Bachthaler, G. – Changes in arable weed infestations with modern crop husbandry techniques. Abst. 6th International Congress for Plant Protection, Vienna. (1967) pp. 167-168 29 – UK Pesticide Guide 2012 – Section 2: BCPC and CABI Publishing 6 – Radowsevich, S. R., and Holt, J. S. – Weed Ecology – Implications for Vegetation Management, 30 – Andersen, R. N. – Germination and establishment of weeds for experimental purposes, p.134 pp. 204-205 31 – Peeters, A. – Poa pratensis – an FAO summary 7 – Hance, R. J. and Holly, K. – Weed Control Handbook – Principles (8th Edition), pp.14, 25, 60-61, 510 32 – Budd, E. – Seasonal germination patterns of Poa trivialis and subsequent plant behaviour. (1967/68) 8 – Evans, S. A. – Weed Destruction, p. 97. Blackwell Scientific Publications. (1962) 33 – Rund, T. – CROPS – 4/10/1997; after Lutman, P. and Wright, K. 9 – Jensen, J. A., Andreasen, C. – The Poa Species: Problems and Management in Danish Arable Fields. Proc. Brighton Crop Protection Conference – Weeds – 1993, pp. 89-94 34 – Firbank, I. G., Norton, L. R. and Smart, S. M. – Recording cereal field margins in Countryside Survey 2000 10 – Wooley, E. W. and Sherrott, A. F. - Determination of the Economic Thresholds of Populations of Poa annua 35 – Froud-Williams, R. J. – Dormancy and germination of arable grass-weeds. Aspects of Applied Biology – 9, in Winter Cereals. Proc. Brighton Crop Protection Conference: Weeds – 1993, pp. 95-100 1985. The biology and control of weeds in cereals 11 – Salisbury, Sir E. – Weeds and Aliens. (1964) pp. 172-173 36 – Harvey, J. J. – Control of Poa spp. in winter cereals – is it worthwhile? Aspects of Applied Biology – 9, 1985. The biology and control of weeds in cereals 12 – Behrendt, S. and Hanf, M. – Grass-Weeds in World Agriculture. (BASF), pp. 82-85 37 – Hewson, R. T. and Read, M. A. – Control of meadow-grasses and broadleaved weeds in cereals with 13 – Okunuki, S. – World Graminaceous Plants. Nippon Soda Company Ltd. post-emergence isoproturon mixtures. Aspects of Applied Biology – 9, 1985. The biology and control of weeds in cereals 14 – Butcher, R. W. – A New Illustrated British Flora, Part II. (1961) 38 – Mortimer, A. M. – On Weed Demography – Recent Advances in Weed Control – 1983 15 – Tutin, T. – A contribution to the experimental taxonomy of Poa annua: Watsonia 4, pp. 1-10 39 – Clarke, J. H. Melander, B. and Orlando, D. – Comparison of the effect of weed control strategies for 16 – Holm, L., Doll, J., Holm, E., Pancho, J. and Herberger, J. – World Weeds – Natural Histories and rotational set-aside in United Kingdom, Denmark and France – Brighton Crop Protection Conference Distribution, pp. 592-593 – Weeds – 1995 17 – Wells, G. – The biology of Poa annua and its significance in grasslands. Herbage Abstr. 44. (1974) 40 – Blair, A. M, Cussans, J. W. and Lutman, P. J. W. – A biological framework for developing a weed pp. 385-391 management support system for weed control in winter wheat: Weed competition and time of weed 18 – Beard, J. – Turfgrass – Science and culture. Prentice-Hall Inc., Englewood Cliffs New Jersey, USA control. The 1999 Brighton Conference – Weeds 19 – Clifford, H. – Seed dispersal on footwear: Proceedings of the Botanical Society of the British Isles (1956) 41 – Williams, G. H. – Elsevier’s Dictionary of Weeds of Western Europe (EWRS). (1982) 20 – Chancellor, R. – Emergence of weed seedlings in the field and the effects of the different frequencies of 42 – Marshall, E. J. P. – Field and field edge floras under different herbicide regimes at the Boxworth E. H. F. cultivation. Proc. 7th British Weed Control Conference, pp. 599-606 (1964) – Initial studies: 1985 British Crop Protection Conference – Weeds 21 – Grime, J. P., Hodgson, J. G. and Hunt, R. – Comparative plant Ecology – A functional approach to 43 – Roberts, H. A. and Potter, Margaret E. – Emergence patterns of seedlings in relation to cultivation common British species, pp. 442-443 and rainfall – Weed Research. Volume 20. (1980) pp. 377-386 22 – Roebuck, J. F. – Agricultural problems of weeds on the crop headland. BCPC Monograph no. 35. 44 – Boatman, N. – Weed management in field margins – Farmland report 1987/88, pp. 76-79 Field Margins. (1987) pp. 11-22 45 – dmr-kynetec Ltd., 2011 Data 23 – Marshall, E. J. P. and Smith, B. D. – Field and margin flora and fauna; interaction with agriculture. BCPC Monograph no. 35. Field Margins. (1987) pp. 23-33 24 – Chancellor, R. J. and Froud-Williams, R.J. – Weeds of cereals in Central Southern England. Weed Research Organisation. 10th Report: 1982-83, pp. 27-32

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